Improve suggestion messages for 'prefer-single-boolean-return' (#346)

Author: vilchik-elena

src/rules/prefer-single-boolean-return.ts

@@ -31,9 +31,10 @@ const rule: TSESLint.RuleModule<string, string[]> = {
   meta: {
     messages: {
       replaceIfThenElseByReturn: 'Replace this if-then-else flow by a single return statement.',
-      suggestIfThenElseReplacement: 'Replace with single return statement',
-      suggestUnsafeIfThenElseReplacement:
-        'Replace with single return statement (beware of return value usages)',
+      suggest: 'Replace with single return statement',
+      suggestCast: 'Replace with single return statement using "!!" cast',
+      suggestBoolean:
+        'Replace with single return statement without cast (condition should be boolean!)',
     },
     schema: [],
     type: 'suggestion',
@@ -115,27 +116,17 @@ const rule: TSESLint.RuleModule<string, string[]> = {
       const shouldNegate = isReturningFalse(ifStmt.consequent);
       const shouldCast = !isBooleanExpression(ifStmt.test);
       const testText = context.getSourceCode().getText(ifStmt.test);
-      let safeCondition: string;
+
       if (shouldNegate) {
-        safeCondition = `!(${testText})`;
-      } else if (shouldCast) {
-        safeCondition = `!!(${testText})`;
+        return [{ messageId: 'suggest', fix: getFix(`!(${testText})`) }];
+      } else if (!shouldCast) {
+        return [{ messageId: 'suggest', fix: getFix(testText) }];
       } else {
-        safeCondition = testText;
-      }
-      const suggestions: TSESLint.ReportSuggestionArray<string> = [
-        {
-          messageId: 'suggestIfThenElseReplacement',
-          fix: getFix(safeCondition),
-        },
-      ];
-      if (shouldCast && !shouldNegate) {
-        suggestions.push({
-          messageId: 'suggestUnsafeIfThenElseReplacement',
-          fix: getFix(testText),
-        });
+        return [
+          { messageId: 'suggestCast', fix: getFix(`!!(${testText})`) },
+          { messageId: 'suggestBoolean', fix: getFix(testText) },
+        ];
       }
-      return suggestions;
     }
 
     function isReturningFalse(stmt: TSESTree.Statement): boolean {

tests/rules/prefer-single-boolean-return.test.ts

@@ -244,7 +244,7 @@ function foo() {
           messageId: 'replaceIfThenElseByReturn',
           suggestions: [
             {
-              messageId: 'suggestIfThenElseReplacement',
+              messageId: 'suggestCast',
               output: `
 function foo() {
   if (bar()) {
@@ -254,7 +254,7 @@ function foo() {
 }`,
             },
             {
-              messageId: 'suggestUnsafeIfThenElseReplacement',
+              messageId: 'suggestBoolean',
               output: `
 function foo() {
   if (bar()) {
@@ -283,7 +283,7 @@ function foo() {
           messageId: 'replaceIfThenElseByReturn',
           suggestions: [
             {
-              messageId: 'suggestIfThenElseReplacement',
+              messageId: 'suggestCast',
               output: `
 function foo() {
   if (bar()) {
@@ -293,7 +293,7 @@ function foo() {
 }`,
             },
             {
-              messageId: 'suggestUnsafeIfThenElseReplacement',
+              messageId: 'suggestBoolean',
               output: `
 function foo() {
   if (bar()) {
@@ -320,7 +320,7 @@ function foo() {
           messageId: 'replaceIfThenElseByReturn',
           suggestions: [
             {
-              messageId: 'suggestIfThenElseReplacement',
+              messageId: 'suggest',
               output: `
 function foo() {
   return !bar();
@@ -344,7 +344,7 @@ function foo() {
           messageId: 'replaceIfThenElseByReturn',
           suggestions: [
             {
-              messageId: 'suggestIfThenElseReplacement',
+              messageId: 'suggest',
               output: `
 function foo() {
   return bar() > 0;
@@ -368,7 +368,7 @@ function foo() {
           messageId: 'replaceIfThenElseByReturn',
           suggestions: [
             {
-              messageId: 'suggestIfThenElseReplacement',
+              messageId: 'suggest',
               output: `
 function foo() {
   return !(baz() > 0);
@@ -392,7 +392,7 @@ function foo() {
           messageId: 'replaceIfThenElseByReturn',
           suggestions: [
             {
-              messageId: 'suggestIfThenElseReplacement',
+              messageId: 'suggest',
               output: `
 function foo() {
   return !(baz());